Advances in technology have led to improvements in the precision of guided munitions. As guidance systems have become more sophisticated, however, the need for even greater precision and performance is apparent. As military targets are frequently found in civilian surroundings, high performance guided munitions are necessary to destroy the targets while minimizing collateral damage. A typical approach to increase the precision of guided munitions is the application of a laser designator to illuminate the desired target. The laser signal in the form of light or electromagnetic radiation (also referred to as “radiation”) reflected from the target propagates to a detector (or sensor) of the guided munition. The guidance system including a detection system (e.g., a quadrant detection system) within the radome of the guided munition guides the munition to augment the reflected laser signal received from the illuminated target.
While such laser guided munitions have been in operation for quite some time, the radome/detector design may limit the velocity of the guided munitions. In particular, many of the radome/detector designs include a hemispherical radome. The velocity of a guided munition having a hemispherical radome may be limited due to the radome's aerodynamic drag. In an effort to reduce this aerodynamic drag, the use of more aerodynamic conformal (such as conical-shaped) radomes has been attempted. This change in the radome shape, however, has created problems for the detection system used to guide the guided munition. For example, such aerodynamic radomes typically suffer from limited field of view and poor detection of small and/or distant targets. Some designs include windows or waveguides that conform to the outer surface of the munition or radome. Some of the designs, however, suffer from the same problems as the conical-shaped radomes.
In addition to the aerodynamic drag and the limited field of view regarding the radome designs, the detection systems often employ a substantial portion of the fore end (or nose) of the guided munitions. This is exacerbated by a reduction in size of the guided munitions. As a result, the warhead and other sections of the guidance system (apart from the detection system) are typically limited to a space outside of the fore end of the guided munitions.
What is needed in the art, therefore, is an optical window for a detection system employable in a guided munition or other application that overcomes the deficiencies in the prior art.